“It should be a prolonged period of fine weather for most people,” she said. “Everyone’s hoping it will go into a second week but we’ll all have to be a little bit cautious at the moment.”

Only Scotland and Northern Ireland are likely to miss out on the summer weather.

Hotel chains have meanwhile reported a spike in bookings for their coastal hotels.

A Travelodge spokesman said: “As forecasters have predicted a sizzling July we have experienced a substantial spike in room bookings for the summer period as well as a double digit increase in most of our coastal hotels for the forthcoming heat wave weekend.”

Almost two thirds (65%) of Britons are expected to holiday at home this year instead of travelling abroad, the hotel chain said.